Platen press with work moving conveyor



United States Patent "ice 3,146,652 PLATEN PRESS WITH WORK MOVING CONVEYOR Bruno de Kalberrnatten, Lausanne, Switzerland, assignor to J. BObst and Son S.A., Prilly, Switzerland, a corporation of Switzerland Filed Feb. 4, 1963, Ser. No. 256,076 Claims priority, application Switzerland Feb. 12, 1962 4 Claims. (Cl. 83-277) This invention pertains to platen presses and more particularly to platen presses wherein sheet stock is fed to the press by conveying bars which are moved by chain drives.

With such presses it is possible for a bar to be stuck between the platens so that when the platens are driven toward each other they engage and damage the tool.

It is accordingly an object of the invention to provide means in a platen press of the type hereinabove described, which prevents damage when a bar is stuck between the platens.

Other objects, features and advantages of the invention will be apparent from the following detailed description of the invention when read with the accompanying drawings wherein:

FIGURE 1 is a diagrammatic view of a platen press, wherein sheet stock is fed to the pressing members by conveying bars which are moved by chain drives;

FIGURE 2 is a cross-sectional view of the platen press incorporating one embodiment of the invention; and

FIGURE 3 is a cross-sectional view of the platen press incorporating another embodiment of the invention.

Referring to FIG. 1, there is shown a platen press which includes platens 1 and 2 as the pressing members.

On either side of the platens 1 and 2 run endless chains 3 between which are conveying bars 4. Bars 4 are preferably provided with grips designed to seize the sheet stock to be worked, for instance paper or cardboard.

These sheets are seized at a first station which is a continuation of the chain drive wheels 6, where the bars 4 are successively stopped in a predetermined position against the stops 7.

Thereafter the sheets are brought between the platens 1 and 2, while each successive bar 4 is stopped at the working station by the stops 8.

The passage of the bars 4 between the platens 1 and 2 takes place when the platens are separated from each other.

Now, it may happen that for some reason or other a bar 4 becomes stuck between the platens 1 and 2 when the latter approach each other, i.e., when the press starts to apply pressure. Obviously, the result of such an accident is not only the at least partial destruction of the bar thus engaged, but also that of a part of the tool and the back-plate fixed to the platens.

Many devices have already been proposed to immobilize the press in such an event. These devices have met with varying success. According to the invention there is provided either an additional safety device or even a sole means of protection for the press. The device includes a strut forming element on either side of the platens and is located in such a way that it constitutes a stop which, in cooperation with a bar and on the passage of the latter between the platens, opposes an approach of the platens, which is likely to cause the mentioned destructive effect.

FIGS. 2 and 3 show two embodiments of the safety drive according to the invention, given by way of example; FIG. 2 is an embodiment wherein the safety devices or protective elements are supported by the bars themselves,

3,146,652 Patented Sept. 1, 1964 and FIG. 3 is an embodiment where they are borne by the platen to which is fixed the tool to be protected.

Both figures are cross-sections of the press.

In FIG. 2 the upper bed or platen 1 carries a tool made of a rigid frame 9 surrounding and supporting the means designed to maintain steel punches 10 in wooden blocks 11 (a tool intended for punching). The lower bed or platen 2 carries a back-plate 12.

in between the platens 1 and 2 runs a conveying bar 13 driven by chains 14. At 15 is the press body.

The bar 13 carries at each of its ends and on either side of the tool, i.e. outside the profile of the sensitive parts of the latter, a block 16 placed so as to be able to engage the rigid frame 9 of the tool. It is apparent that when the press operates, the bar 13 being engaged between the platens 1 and 2, the bar ends will be pressed against the back-plate 12, whilst the superposed blocks 16 and frame 9 will oppose an approach of the platens likely to injure the tool, i.e., for the example given, the steel punches 10 and wooden blocks 11.

it is clear that each conveying bar 13 will carry and drive with it two such protective blocks 16 which, at the stations fixed by the stops 7 and 8 (fig. 1) will not oppose the approach of the platens 1 and 2.

In the second embodiment according to FIG. 3 the protective elements are borne by the upper platen 1 and constitute, in the present case, an extension 17 of the frame 18 of the tool 19. Instead of being permanently fixed to the frame 18, these extensions could be detacha ble elements on the frame 18 or even formed from particular pieces fitted to the platen 1.

The effect obtained is the same as in the first example, i.e., the clearance provided for by extension 17 opposes an approach of the platen which is dangerous to the tool. The tool is thus protected.

What is claimed is:

1. In a platen press which includes a pair of opposedly movable platens, at least one of the latter carrying a tool and a conveyor means including conveyor bars which move between the platens to position sheet stock opposite said tool, apparatus for preventing the approach of said platens suificiently close to each other to damage said tool when said conveyor bars are between said platens, comprising blocks disposed on the ends of said conveyor bars and laterally clearing said tool, said blocks extending toward said tool carrying platen and having a thickness so as to prevent said tool from contacting a conveyor bar when said platens approach each other when a conveyor bar is between said platens.

2. In a platen press which includes a pair of opposedly movable platens, at least one of the latter carrying a tool and a conveyor means including conveyor bars which move between the platens to position sheet stock opposite said tool, apparatus for preventing the approach of said platens sufi'iciently close to each other to damage said tool when said conveyor bars are between said platens, comprising means for supporting said tool on one of said platens and blocking means disposed adjacent the sides of said supporting means and extending toward said conveyor bars and beyond the extremities of said tool for contacting a conveyor positioned between said platens when said platens approach each other when a conveyor bar is between said platens.

3. The combination of claim 2, wherein said blocking means is fixed to the platen carrying the tool.

4. The combination of claim 2 wherein said blocking means is fixed to said supporting means.

References Cited in the file of this patent FOREIGN PATENTS 1,045,781 Germany Dec. 4, 1958 

1. IN A PLATEN PRESS WHICH INCLUDES A PAIR OF OPPOSEDLY MOVABLE PLATENS, AT LEAST ONE OF THE LATTER CARRYING A TOOL AND A CONVEYOR MEANS INCLUDING CONVEYOR BARS WHICH MOVE BETWEEN THE PLATENS TO POSITION SHEET STOCK OPPOSITE SAID TOOL, APPARATUS FOR PREVENTING THE APPROACH OF SAID PLATENS SUFFICIENTLY CLOSE TO EACH OTHER TO DAMAGE SAID TOOL WHEN SAID CONVEYOR BARS ARE BETWEEN SAID PLATENS, COMPRISING BLOCKS DISPOSED ON THE ENDS OF SAID CONVEYOR BARS AND LATERALLY CLEARING SAID TOOL, SAID BLOCKS EXTENDING 